Tissue culture experiments are usually carried out by placing tissue cells in a culture flask within a suitable medium and adding suitable chemicals while observing cellular activity and growth. It is not uncommon to take time lapse photographs through the culture flasks to make a permanent record of growth.
The major problem with the foregoing procedure is a consequence of the fact that the medium in the flask has to be changed as often as three or four days. As a consequence, the field one is photographing is therefore often changed. It is evident that improved results could be realized if the cellular growth could be recorded over an extended period of time, substantially longer than three or four days with substantially the same background and environment.
In addition to the above, studying the cellular activities in a tissue culture from a given patient does not provide the same information as would be obtained if the cellular activity could be examined while growth is taking place in the patient's body. In this latter event, the effects of any chemotherapeutic regimen on the patient's own tumor cells could readily be monitored.
At the present time, approximately only five per cent (5%) of all tumors of human origin can be cultivated and examined.